Ok makes sense. When I finish installing mine on the 40 I am going to have a play with the best setup. It's so basic it just has a vacuum device(don't know technical term) connected to a bar that open and shuts the gate that takes it pressure from the inlet just after the turbo. I think as the vacuum builds it keeps it shut tight, when you let off the accelerator it pops open momentarily then is shut again. So i could have manual control but as the injector pump will have to be turned up to throw in more fuel, it's going to get confused if sometimes the waste gate is left open. Ramble ramble, honestly it makes sense in my head!